He applied the “Page 99 Test” to Confessions of an Alien Hunter and described the experience as follows:

Do we share the Milky Way with some clever company? Do the star fields of our cosmic metropolis shelter species that, by any reasonable measure, are as accomplished as Homo sapiens?

Grab the next dozen astronomers off the street and ask them if they think extraterrestrial life is superabundant or scarce, and I assure you that an imposing majority will opine that our universe probably teems with protoplasm. Consider the fact that life – mostly of the single-celled variety – occupies every remotely tenable niche on Earth.

Many worlds might sport some sort of alien pond scum. But success in the search for E.T. is dependent on another question: will worlds with life frequently gin up our functional equivalents – creatures that are clever enough to understand science and build powerful radio transmitters or lasers that would give away their presence?

We don’t know if they will or won’t, and the pleasing assumption that life commonly begets intelligence is controversial. Readers who perversely confine their perusal of this book to page 99 will land in the middle of a gedankenexperiment that exposes the nature of this problem. Suppose the dinosaurs hadn’t been wiped out. Would we – or some other intelligent beings – still arise, and eventually be of sufficient refinement to stack those dino remains in museums? This is a legitimate query, because these creatures (and most of their land-dwelling brethren) would still be walking the planet if the asteroid that spelled their doom had arrived in our vicinity only 20 hours earlier, to sail by without notice or incident.

Page 99 considers the possibility that either the dinosaurs or some other animal would have eventually developed human-level intelligence, assuming Earth’s flora and fauna were spared the great Cretaceous-Tertiary extinction. Canadian paleontologist Dale Russell tried “evolving forward” the cleverest of the dinosaurs – Stenonychosaurus – to see if, after 65 million years of Darwinian selection, it might have become a worthy doppelganger for ourselves. Russell believed such a development was likely, but the jury (read: evolutionary biologists) has yet to agree. After all, the dinosaurs strutted the Earth for 150 million years – plenty of time to get clever. They botched the job.

This might suggest that cosmic intelligence is rare, even if cosmic life is abundant. But any reader who continues beyond page 99 will learn about new research hinting that – given complex animal life and enough time – sentience will be a commonplace development, even if the dinosaurs weren’t going down that road. If this is true, our telescopes may soon discover that humans are not the cleverest kids on the galactic block.